Spinal diagnostic methods and apparatus

ABSTRACT

Methods, devices and systems facilitate diagnosis, and in some cases treatment, of back pain originating in intervertebral discs. Methods generally involve introducing one or more substances into one or more discs using a catheter device. In one embodiment, a patient assumes a position that causes back pain, and a substance such as an anesthetic or analgesic is introduced into the disc to determine whether the substance relieves the pain. Injections into multiple discs may optionally be performed, to help pinpoint a disc as a source of the patient&#39;s pain. In some embodiments, the catheter device is left in place, and possibly coupled with another implantable device, to provide treatment of one or more discs. A catheter device includes at least one anchoring member for maintaining a distal portion of the catheter within a disc.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a Continuation-in-Part of application Ser. No.10/825,961, filed on Apr. 16, 2004, and is a continuation of U.S.application Ser. No. 11/597,349, which claims priority under 35 USC 371from PCT/US2005/012981, filed on Apr. 15, 2005, the full disclosures ofwhich are incorporated herein by reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention generally relates to medical devices and methods.More particularly, the present invention relates to devices and methodsfor diagnosing and/or treating spinal pain

Back pain takes an enormous toll on the health and productivity ofpeople around the world. According to the American Academy of OrthopedicSurgeons, approximately 80 percent of Americans will experience backpain at some time in their life. In just the year 2000, approximately 26million visits were made to physicians' offices due to back problems inthe United States. On any one day, it is estimated that 5% of theworking population in America is disabled by back pain.

Unfortunately, back pain is not only extremely common, but can also bedifficult to accurately diagnose and effectively treat. Challenges stemfrom the fact that it is often difficult to pinpoint exactly what iscausing a patient's pain or even where the pain originates. Although anumber of effective treatments exist for various types of back pain, anumber of them are highly invasive and may actually exacerbate pain orcause pain in other parts of the back. Therefore, due to the challengesinvolved in diagnosing and treating back pain, and fueled by the largenumber of patients suffering from back pain, improved diagnostic andtreatment methods and devices and constantly being sought.

Back pain may be classified into two general categories: (1) “axialspinal pain,” which arises from pathology or dysfunction in thestructural components of the spine, such as the vertebrae or theintervertebral discs between the vertebrae; and (2) “radicular pain,”which originates from pressure on or irritation of nerve roots.Radicular pain is often relatively simple to diagnose and pinpoint,because pain tends to radiate from irritated nerve roots out into thebody in predictable patterns, and nerve root compression can often beseen on an MRI study or other radiological study of the spine. Treatmentof radicular pain is also often quite straightforward, typicallyinvolving injections or surgical procedures to decrease inflammation inor remove the structures impinging on the effected nerve root.

In contrast to radicular pain, axial spinal pain is typically much moredifficult to diagnose and localize. “Discogenic pain,” for example,which is a type of spinal pain originating in one or more intervertebraldiscs (soft tissue structures between vertebrae of the spine), isparticularly difficult to diagnose and pinpoint to one or more specificdiscs. The physical examination and complaints of the patient typicallyprovide only general clues as to the actual cause and originatinglocation of the pain, and no currently available radiological studiescan accurately assess which of a patient's discs (if any) is causingdiscogenic pain. Adding to the difficulty of diagnosis is the fact thatmany different factors may lead to discogenic pain. Furthermore, it isoften difficult to determine whether treatment of a disc (or discs) willactually alleviate the patient's pain or whether there are otherunderlying causes of the pain that will remain even after a disc istreated. Therefore, diagnosing and treating discogenic pain can often beincredibly challenging, and there is always a risk that surgery will beperformed unnecessarily or will fail to relieve the patient's back pain.

The most commonly performed surgical procedure for treating discogenicpain is spinal fusion, in which adjacent vertebrae above and below thedisc causing pain are fused together to prevent motion, thus bypassingthe painful disc. Spinal fusion can be a very effective treatment, butit is relatively costly and invasive, and may be associated with aprolonged recovery and a number of potential complications. For example,fusion may sometimes lead to accelerated degeneration of one or morediscs adjacent the treated disc due to increased forces placed on theadjacent discs from the fusion. Another possible treatment of discogenicpain involves replacement of the disc with an artificial (prosthetic)disc. This treatment may allow for better patient mobility than spinalfusion, but this treatment option is still in its infancy. Regardless ofthe method used to treat discogenic pain, an accurate diagnosis isessential for the treatment's success.

Despite the importance of obtaining a correct and specific diagnosis ofdiscogenic pain, currently available diagnostic techniques have a numberof drawbacks. A diagnostic test referred to as “discography” is the mostcommonly used and accepted diagnostic technique. Discography involvesinserting a needle into an intervertebral disc and injecting a contrastdye into the compliant inner core of the disc (the nucleus pulposus)under pressure. A radiograph (or “X-ray”) of the spine is then taken.Sometimes, anatomical defects of the disc, such as tears in the fibrousouter layer of the disc (the annulus fibrosis) can been seen on aradiograph, which may be indicative of a possible cause of pain.Additionally, the injection of contrast into the disc under pressure hasbeen shown to sometimes cause the patient to feel pain, caused by thechemical composition of the contrast and/or by increased pressure withinthe nucleus pulposus. Sometimes this pain mimics the back pain that thepatient usually feels during daily activities. Through a combination ofsubjective analysis of radiographs and a subjective description of theback pain by the patient, the physician attempts to determine whetherthe particular disc is causing the patient's pain. In some instances,multiple discs on one patient are injected during a diagnosticprocedure.

Some clinicians theorize that if a discogram is positive according tocommonly used criteria, then the tested disc is the source of thepatient's pain. However, there is no universally accepted definition ofthe criteria for a positive discogram. As a result, interpretation ofdiscograms has been a longstanding controversy. Not only does the testrely on subjective feedback, but results themselves have been shown tohave a high rate of false positives and false negatives, with up to30-40% of patients with no back pain having positive discograms.Similarly, some patients have reported feeling a replication of theirusual pain during discography, even though it is later found thatanother, non-discogenic cause was the actual origin of the pain. Thesefacts demonstrate that the traditional discogram is not highly specific.

A number of currently available epidural catheters and techniquesprovide for injecting substances, typically anesthetics, into anepidural space of a spine. Examples of such epidural catheters aredescribed in U.S. Pat. Nos.: 3,885,561; 4,737,146; 4,973,305; 5,004,456;5,024,655; 5,084,016; 5,129,889; 5,234,406; 5,344,439; 5,800,407;6,676,643 and 6,368,315. Such catheters, however, are not adapted fordelivery into an intervertebral disc. Furthermore, injecting substancesinto the epidural space is not helpful for diagnosing discogenic pain.

Due to the prevalence of discogenic pain and other types of back pain,the difficulty of accurately diagnosing and pinpointing discogenic pain,and the invasive nature of typical discogenic pain treatment techniquessuch as spinal fusion, improved methods and apparatus for diagnosingand/or treating discogenic pain are needed. Ideally, such methods andapparatus would enhance a physician's ability to pinpoint one or morediscs that are causing a patient pain, thus enhancing or replacingtraditional discography. Also ideally, these methods and devices wouldbe no more invasive, or perhaps even less invasive, than discography.Even more ideally, variations of techniques and devices for diagnosingdiscogenic pain could also be used to treat back pain in someindividuals, thus providing less invasive alternatives to traditionalspinal fusion and other surgical techniques. At least some of theseobjectives will be met by the present invention.

BRIEF SUMMARY OF THE INVENTION

Methods and devices of the present invention generally facilitatediagnosis, and in some cases treatment, of discogenic pain. Morespecifically, methods and devices of the invention help determinewhether one or more intervertebral discs in a patient are actuallycausing the patient's back pain, and also help pinpoint which disc ordiscs are causing the pain. In one embodiment, a distal portion of acatheter device is positioned transannularly or transosseously in anintervertebral disc that is thought to be the cause of the patient'spain. One or more anchoring members are then used to maintain the distalportion in the disc. The patient is asked to assume a position orperform a task, such as bending over, which typically causes the patientto experience back pain. Using the catheter device, one or moresubstances, such as an anesthetic or analgesic, are injected into thedisc. The patient then reports whether the anesthetic has alleviated thepain. Optionally, additional intervertebral discs may be tested, one ormore placebo injections may be used, a conventional discography may beadded to the procedure and/or the like. Based on the patient's responseto the introduction of substance(s) into the disc (or discs), adetermination may be made as to whether one or more specific discs arecausing the patient's pain. Diagnostic and treatment decisions may bebased on such a determination.

An “intervertebral disc” is generally referred to herein as soft tissuebetween any two adjacent vertebrae. An intervertebral disc generallyincludes a fibrous outer layer called the “annulus fibrosis” and a morecompliant inner core called the “nucleus pulposus.” In variousembodiments, substances may be introduced into an annulus fibrosis,nucleus pulposus, or both. To the extent that other soft tissues betweentwo adjacent vertebrae may also be considered part of an intervertebraldisc, it is contemplated within the scope of the invention that one ormore substances may be introduced into such soft tissues as well.

In some cases, devices and methods for diagnosing discogenic pain mayalso be used for treating pain. Catheter devices of the inventiongenerally include one or more anchoring members for maintaining a distalportion of the catheter device in a position within a disc. Such acatheter device may be coupled with, for example, an implantable pump orinjection port, and the pump or port may be used to supply one or moresubstances, such as anesthetic or analgesic, to the disc to treat apatient's back pain. Many other substances may be introduced to thedisc, as discussed fully below, and other treatment modalities arepossible, such as transcutaneous electrical nerve stimulation (TENS).

In one aspect of the present invention, a method for introducing one ormore substances into an intervertebral disc involves positioning adistal portion of a catheter device in the disc, anchoring the distalportion of the catheter device to maintain the distal portion in thedisc, and introducing at least one substance into the disc through thecatheter device. A number of different methods for positioning thedistal portion may be employed in various embodiments of the invention.In one embodiment, for example, the catheter device is passed through alumen of an introducer device. In one such embodiment, positioning thedistal portion of the catheter involves passing the catheter devicethrough the lumen of the introducer device over a pointed stylet,piercing through an annulus fibrosis of the disc using the stylet, andwithdrawing the stylet from the catheter device. In an alternativeembodiment, positioning the distal portion involves piercing through anannulus fibrosis of the disc into the disc with a tapered distal end ofthe catheter device. In some embodiments, the catheter device is passedover a guidewire.

In various embodiments in which an introducer device is used, theintroducer device may either be advanced to a position within the discor to a position just outside the disc. In either case, the catheterdevice may have a distal end or portion configured to facilitateadvancement of the distal end through the annulus fibrosis. In someembodiments, the catheter device is passed over a guidewire. In somecases, the catheter is passed over the guidewire within the needle,while in alternative embodiments the introducer is removed over theguidewire before the catheter device is passed over the guidewire. Insome embodiments, positioning the distal portion is facilitated byvisualizing at least one radioopaque marker or material at or near thedistal portion to assess its location.

In some embodiments, anchoring the catheter device involves deployingone or more anchoring members disposed along the catheter body. In somecases, such anchoring members may be disposed at or near the distalportion of the catheter, while in other embodiments anchoring may occurat locations farther from the distal portion. In some embodiments,anchoring may be achieved by using a separate anchoring device, such asby applying adhesive, suture or the like to anchor the catheter to thepatient in a desired position. In one embodiment, anchoring involvesinflating at least a first expandable member in the disc. Optionally,this technique may further involve inflating at least a secondexpandable member adjacent an outer surface of the disc, such that thereis one inflatable member in the disc and another inflatable member justoutside the annulus fibrosis.

In an alternative embodiment, anchoring comprises deploying at least onemechanism along the distal portion of the catheter device to increasethe effective cross-sectional diameter of the catheter at one or morelocations. For example, in one embodiment the cross-sectional diameteris increased by releasing one or more shape memory or spring loadedmembers from constraint. In other embodiments, the cross-sectionaldiameter may be increased by actuating one or more mechanical members ormoving an inner catheter shaft of the catheter device relative to anouter catheter shaft of the catheter device to cause one or moreanchoring members to buckle outwards. In another embodiment, anchoringcomprises causing at least part of the distal portion to change from asubstantially straight shape to a substantially curved or geometricshape. And in yet another embodiment, anchoring comprises attaching partof the distal portion to an annulus fibrosis of the disc. For example,the attachment member may be screwed, twisted or pierced into theannulus fibrosis in various embodiments.

In addition to the anchor mechanisms described above, the access andtreatment catheters of the present invention can be modified to promotetissue growth on or into at least selected portions of the catheter.Such tissue growth promotion could be accomplished by modifying theexterior texture or shape of the catheter exterior, or by providingadditional physical structure which would promote tissue ingrowth andattachment. Alternatively or in addition, the catheter could be providedwith an osteogenic substance, drug, or chemical to promote the desiredtissue attachment. Such tissue attachment can be promoted in bone,muscle, fibrotic tissue, scar tissue, chondrocytes, or other tissuewhich occurs in or around the disc space of vertebral bodies. Anchoringby promoting tissue ingrowth is particularly useful when the catheterwill be implanted for an extended length of time, as will often be thecase for therapeutic treatment protocols.

The substance (or substances) introduced into the disc may be anysuitable substance, typically introduced for diagnosis and/or treatmentof discogenic pain, but in alternative embodiments for any othersuitable purpose. Any suitable combination of substances may beintroduced, either simultaneously or sequentially, for diagnosis,treatment or other purposes. In some embodiments, one or more placebosubstances may be introduced into one or more discs, typically to assistin diagnosis but in other embodiments for study or experimental purposesor the like. In some embodiments, for example, introduced substance(s)may include, but are not limited to, an anesthetic; an analgesic; anantibiotic; a hydrating agent such as hypotonic saline, isotonic salineor hypertonic saline; a supportive agent such as a hydrogel,ethylene-vinyl alcohol copolymer, Dimethyl Sulfoxide or Tantalum; aprolotherapy agent such as sodium morrhuate, cod oil, phenol, mineralsor ethyl alcohol; and other agents such as collagen, stem cells,Osteogenic Protein-1, ethanol, alcohol, steroids, radio-opaque contrastagents, ultrasound contrast agent, Bone Morphogenetic Protein (BMP),BMP-2, BMP-4, BMP-6, BMP-7, BMP-12, Serotonin 5-HT2A receptorinhibitors, LMP-1, TIMP-1, TGF-1, TGF-2, Rofecoxib, Ketorolac,Glucosamine, Chondroitin Sulfate, Dextrose, DMSO, non-steroidalantiinflammatory drugs, ibuprofen, naprosyn, Bextra, Vioxx, Celebrex,indomethacin, botulinum toxin, capsaicin, vanilloid agonists, vanilloidantagonists, VR1, VRL-1, steroids, methylprednisolone or chymopapain.Substances may be delivered in a biodegradable or time release vehicleto provide long-term administration of the substances.

Examples of anesthetics and analgesics include, but are not limited tolidocaine, chloroprocaine, mepivacaine, ropivacaine, xylocaine,prilocaine, morphine, bupivocaine, marcaine, 2-chloroprocain, fentanyl,diamorphine, meperidine, methadone, alfentanil, hydromorphone,lofentanil, sufentanil, buprenorphine, other opiates, adrenergicagonists, somatostatin analogs, calcium channel blockers,N-methyl-D-aspartate receptor antagonists, ketamine, benzodiazepines,klonidine, tizanidine, midazolam, levorphanol, heterocyclicantidepressants, nonheterocyclic, serotonin-enhancing antidepressants,GABA analogues, psychogenic amines, somatostatin, octreotide, SNX-111,midazolam, methylprednisolone acetate, Aristospan, ethyl chloride,etidocaine, linocaine, triamcinolone diacatate, Astramorph, Duramorph,Dilaudid, Sensorcaine MPF, Baclofen (Lioresal), Clonidine, baclofen,codeine, neurontin and Demerol. Examples of antibiotics include, but arenot limited to, Penicillins, Cephalosporins, Tetracycline, Erythromycin,Clindamycin, Vancomycin, Bacitracin, Doxycycline, Ampicillin, Levaquin,Metronidazole, Azithromycin, Ciprofloxacin, Augmentin, Bactrim, TMP-SMX,Rocephin, Gentamycin, Keflex and Macrobid.

In some embodiments, the method further involves, before introducing thesubstance, causing the patient to assume a position in which substantialspinal pain is experienced. In such embodiments, the substanceintroduced is often an anesthetic or analgesic, and determining whetherthe patient feels the spinal pain after introduction of the substancehelps determine whether pain is caused by that particular disc. Such amethod may optionally further include positioning a distal portion of asecond catheter device in a second intervertebral disc, anchoring thedistal portion of the second catheter device to maintain the distalportion in the second disc, and introducing at least one substance intothe second disc through the second catheter device. The method may alsoinvolve, before introducing the at least one substance into the seconddisc, causing the patient to assume a position in which substantialspinal pain is experienced, wherein the at least one substance includesat least one anesthetic or analgesic. In some embodiments, the methodinvolves determining which of the discs into which the at least onesubstance was introduced is causing the patient's spinal pain. Suchmethods may optionally further include performing a discographyprocedure on the intervertebral disc before positioning the distalportion of the catheter device in the disc. Alternatively, in otherembodiments the discography procedure may be performed on theintervertebral disc after introducing the at least one anesthetic.

In one embodiment of this method, the at least one substance isintroduced into the disc (or into multiple discs) automatically over aperiod of time. This may involve, for example, coupling the catheterdevice with an automated injection device, which will allow the patientto rest alone in a clinic or hospital room, assume variousback-pain-generating positions or the like, while various substances arebeing introduced into one or more discs. In some embodiments, such amethod may also include recording one or more patient inputs describingback pain experienced by the patient.

Some embodiments of the method further include leaving the catheterdevice in position with the distal portion in the disc and administeringthe at least one substance over time to provide treatment of spinalpain. As mentioned previously, in some embodiments the substance(s) maybe administered over time via a subcutaneous injection port or implantedpump, the method further comprising coupling the catheter device to thesubcutaneous injection port or implanted pump. In alternativeembodiments, the substance(s) may be administered over time via anyother suitable combination of devices or other means.

In another aspect of the present invention, a method for identifying anintervertebral disc that is causing pain involves positioning a distalportion of a catheter device in a disc of a patient, anchoring thedistal portion of the catheter device to maintain the distal portion inthe disc, causing the patient to assume a position in which substantialspinal pain is experienced, and introducing at least one substance intothe disc through the catheter. In this aspect, the method may includeany of the features, steps or variations described above.

In yet another aspect of the present invention, a catheter device forintroducing one or more substances into an intervertebral disc comprisesan elongate flexible catheter body and at least one anchoring memberdisposed along the catheter body for anchoring at least part of thedistal portion of the catheter in the intervertebral disc. The catheterbody itself has a proximal portion, a self-introducing distal portionfor facilitating penetration of an annulus fibrosis of the disc, and atleast one lumen for introducing one or more substances into theintervertebral disc. By “self-introducing,” it is meant that the distalportion of the catheter body has at least one feature that facilitatespenetration of an annulus fibrosis by the distal portion.

In some embodiments, the anchoring member is disposed on or near thedistal portion of the catheter, while in other embodiments it may belocated farther from the distal portion or may even be a separate deviceused to anchor the catheter. In various embodiments, the anchoringmember (or multiple anchoring members) of the catheter device may takeany of a number of various forms. For example, in one embodiment theanchoring member comprises at least one expandable member coupled withan inflation lumen. In an alternative embodiment, the anchoring membercomprises at least one shape memory, spring loaded or mechanicallyactivated member for increasing the effective cross-sectional diameterof the catheter body at or near the distal portion. Alternatively, theanchoring member may comprise at least one outwardly buckling membercoupled with an inner catheter shaft and an outer catheter shaft of thecatheter body so as to outwardly buckle when the inner shaft is movedaxially relative to the outer shaft. In yet another embodiment, theanchoring member comprises at least one attachment member for attachingto an annulus fibrosis of the disc. Such an attachment member, forexample, may include at least one threaded surface, spiral needle or thelike. In another embodiment, the anchoring member comprises at least onedeformable member to change at least part of the distal portion from asubstantially straight shape to a substantially curved or geometricshape.

In various embodiments, the catheter body may have any suitableconfiguration, dimensions, features or the like. For example, in oneembodiment the self-introducing distal portion of the catheter bodycomprises at least one pushable portion, the pushable portion having astiffness greater than adjacent portions of the catheter body.Optionally, the self-introducing portion may further comprise a tapereddistal end of the catheter device. In some embodiments, the device mayinclude a pointed stylet removably disposed within a lumen of thecatheter device for piercing through the annulus fibrosis of the disc.

A number of features may facilitate passage of the catheter body throughan introducer device. For example, in one embodiment the catheter bodyincludes a friction resistant outer surface. In some embodiments, theouter diameter of the catheter body is less than 2 mm. Also in someembodiments, a cross-sectional diameter of the catheter body is largernear a proximal end of the body than near a distal end of the body.Optionally, the catheter body may also include an outer surface havingone or more markings for indicating depth of insertion of the catheterdevice into a patient's body. In alternative embodiments, the catheterbody may include an outer surface having two or more different colorsfor indicating depth of insertion of the catheter device into apatient's body. The catheter body may further include at least oneradioopaque marker or material for facilitating visualization of thecatheter device in a patient.

In one embodiment, the catheter device includes an injection tubeextending through at least part of the lumen of the catheter body forintroducing one or more substances into the disc and an inflation tubeextending through at least part of the lumen for expanding thedeployable anchoring member. The injection tube may be made of anysuitable material or combination of materials, such as but not limitedto stainless steel, tempered stainless steel, annealed stainless steel,polymers, and superelastic alloys. In some embodiments, the injectionand inflation tubes exit a proximal end of the catheter body and areremovably coupled with at least one adapter to provide for injection andinflation. In some embodiments, the injection and inflation tubes extendthrough at least part of the catheter body lumen coaxially.Alternatively, the injection and inflation tubes may extend through atleast part of the catheter body lumen side-by-side. In otherembodiments, the injection and inflation tubes may extend through partof the catheter body lumen coaxially and through another part of thelumen side-by-side. In an alternative embodiment of the catheter device,the catheter body does not include injection and inflation tubes butinstead comprises a single extrusion having an injection lumen forintroducing one or more substances into the disc and an inflation lumenfor expanding the at least one anchoring member.

In various embodiments, the catheter device may have any suitableproximal end configurations for providing connection to one or moreinjection, inflation, suction, irrigation or other devices, forproviding guidewire access and/or the like. In one embodiment, forexample, a proximal end of the proximal portion of the catheter body isbifurcated into two separate catheter body proximal ends. In someembodiments, each of the two proximal ends is removably coupled with anadapter for facilitating injection or inflation via either end. Someembodiments of the device also include a guidewire having a distal endshaped to maintain the distal end within the disc. Such a distal end mayinclude, for example, a double guidewire, a coil or a pigtail. Suchguidewires can be made from any conventional guidewire material,including stainless steels and superelastic materials such asnickel-titanium alloys. Generally, the use of superelastic guidewires ispreferred since other materials, such as stainless steel, mayinadvertently kink in a location distal to the tip of the catheter as itis being advanced. If the guidewire kinks, it can be difficult to removethe guidewire from the catheter, interfering with the remainder of theprocedure.

It will also be preferred in some instances to provide a guidewire withradioopaque markers. The guidewire will have a small diameter, andsuperelastic materials, such as nitinol, have low visibility underfluoroscopic imaging. The radioopacity of the guidewire can be improvedby adding a radiopaque material in a variety of conventional ways. Forexample, the guidewire can be coated with the radioopaque material, aradioopaque core may be provided within the guidewire, a radioopaquematerial may be braided over the guidewire, or the material provided asring-like markers. Such coated guidewires having improved radioopacitycan be manufactured in a variety of ways, including sputtering,electroplating, electroless plating, and the like.

In another aspect of the invention, a system for introducing one or moresubstances into an intervertebral disc includes an introducer device anda catheter device passable through the introducer device. The catheterdevice includes an elongate flexible catheter body and at least onedeployable anchoring member disposed along the catheter body foranchoring at least part of the distal portion of the catheter in thedisc. The catheter body includes a proximal portion, a self-introducingdistal portion for facilitating penetration of an annulus fibrosis ofthe disc, and at least one lumen for introducing one or more substancesinto the intervertebral disc. In various embodiments, the catheterdevice may include any of the features, configurations or combinationsdescribed above.

In some embodiments, the system further includes a pointed styletremovably disposed within a lumen of the catheter device for piercingthrough the annulus fibrosis. In some embodiments, the system includes aguidewire over which the catheter device may be passed within theintroducer device. The catheter device and introducer device may haveany suitable dimensions, but in one embodiment the outer diameter of thecatheter body is less than 2 mm. An inner diameter of the needle, insome embodiments, is between about 0.1 mm and about 0.01 mm larger thanthe outer diameter of the catheter body.

In some embodiments, the system may further include an automaticinjection device removably coupled with the catheter device forautomatically introducing the at least one substance into the disc.These or other embodiments may optionally further include a recordingdevice for recording patient inputs describing pain felt by a patient.

In another aspect of the present invention, a kit for introducing one ormore substances into an intervertebral disc includes a catheter device,at least one implantable device removably couplable with the catheterdevice for introducing the one or more substances into a disc over time,and instructions for using the catheter device and implantable device.The catheter device includes: an elongate flexible catheter body havinga proximal portion, a self-introducing distal portion for facilitatingpenetration of an annulus fibrosis of the disc, and at least one lumenfor introducing one or more substances into the intervertebral disc; andat least one anchoring member disposed along the catheter body foranchoring at least part of the distal portion of the catheter within thedisc. This catheter device may have any of the features described above.

The implantable device may include any of a number of suitable devicesin various embodiments. For example, in some embodiments the implantabledevice comprises a pump. In other embodiments, the implantable devicecomprises an injection port.

In various embodiments, the kit may also include one or more additionaldevices, such as but not limited to an introducer device forfacilitating positioning of the catheter device in the disc, a pointedstylet removably disposed within a lumen of the catheter device forpiercing through the annulus fibrosis and/or a guidewire passablethrough the needle.

These and other aspects and embodiments of the present invention aredescribed more fully below with reference to the attached drawingfigures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1K illustrate a method for positioning a catheter device tointroduce a substance into an intervertebral disc, shown from atransverse cross-section of the spinal column, according to oneembodiment of the present invention.

FIGS. 1L and 1M illustrate catheter introduction needles havingsharpened tips (FIG. 1L) and atraumatic tips (FIG. 1M).

FIG. 1N illustrates a catheter-introducing needle having an axial slotand frangible cover to facilitate removal of the needle from over thecatheter after the catheter has been implanted.

FIGS. 2A and 2B illustrate part of a method for positioning a catheterdevice to introduce a substance into an intervertebral disc using apointed stylet, according to one embodiment of the present invention.

FIG. 2C illustrates a catheter device in place for introducing asubstance into an intervertebral disc and an introducer device beingsplit, according to another embodiment of the present invention.

FIGS. 2D and 2E illustrate catheters and stylets having modified distalends to enhance coupling during introduction of the catheter and styletassemblies.

FIGS. 3A and 3B are perspective and cross-sectional views, respectively,of a distal end of a catheter device, according to one embodiment of thepresent invention.

FIGS. 4A and 4B are cross-sectional views of a distal end of a catheterdevice with an anchoring member in an undeployed and deployed state,respectively, according to one embodiment of the present invention.

FIGS. 5A and 5B are cross-sectional views of a distal end of analternative catheter device with an anchoring member in an undeployedand deployed state, respectively, according to another embodiment of thepresent invention.

FIGS. 6A and 6B are cross-sectional views of a distal end of analternative catheter device with an anchoring member in an undeployedand deployed state, respectively, according to another embodiment of thepresent invention.

FIGS. 7A and 7B are perspective views of a distal end of an alternativecatheter device with an anchoring member in an undeployed and deployedstate, respectively, according to another embodiment of the presentinvention.

FIG. 8 illustrates a catheter device having a deforming, anchoringdistal portion, according to one embodiment of the present invention.

FIG. 9 illustrates a catheter device having a deforming, anchoringdistal portion, according to another embodiment of the presentinvention.

FIG. 10A illustrates a longitudinal cross-section of a spinal columnwith a catheter device with a radially symmetric anchor, according toone embodiment of the present invention.

FIG. 10B illustrates a longitudinal cross-section of a spinal columnwith a catheter device with a radially asymmetric anchor, according toanother embodiment of the present invention.

FIG. 10C illustrates a longitudinal cross-section of a spinal columnwith a catheter device with an elliptical shaped anchor, according toanother embodiment of the present invention.

FIG. 10D illustrates a longitudinal cross-section of a spinal columnwith a catheter device with a non-spherically shaped anchor, accordingto another embodiment of the present invention.

FIG. 11 illustrates a spiral anchor for attaching to the annulusfibrosis of an intervertebral disc, according to one embodiment of thepresent invention.

FIG. 12 illustrates a distal end of a catheter device having a threadedportion for attaching to an annulus fibrosis of an intervertebral disc,according to one embodiment of the present invention.

FIG. 13 illustrates a catheter device having two anchoring members foranchoring inside and outside an annulus fibrosis of an intervertebraldisc, according to one embodiment of the present invention.

FIG. 14 illustrates a catheter device coupled with an implanted devicefor facilitating delivery of substances to the intervertebral disc,according to one embodiment of the present invention.

FIGS. 14A and 14B illustrate introduction of a treatment or other accesscatheter into a disc space using a transosseous approach.

FIG. 15A illustrates a catheter device passed over a guidewire having aspiral-shaped distal end, according to one embodiment of the presentinvention.

FIG. 15B illustrates a catheter device passed over a guidewire having azigzag-shaped distal end, according to another embodiment of the presentinvention.

FIGS. 16A and 16B illustrate a double-wire guidewire in undeployed anddeployed states, respectively, according to one embodiment of thepresent invention.

FIGS. 17A and 17B are perspective and cross-sectional views,respectively, of a proximal adapter for use with a catheter device,according to one embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Methods, devices and systems of the present invention generally providefor introduction of one or more substances into an intervertebral discto facilitate diagnosis and/or treatment of discogenic pain (i.e., backpain originating in one or more intervertebral discs). Methods, devicesand systems may be used alone or in conjunction with other methods ordevices that are currently known or hereafter developed, such asdiscography, radiological studies, physical examination and/or the like.In alternative embodiments, methods and devices of the invention may beused for purposes other than diagnosis or treatment, such as for studyor experimental purposes or the like. Therefore, although the followingdescription focuses on diagnostic and therapeutic applications, variousembodiments may be used for any other suitable application.

Referring now to FIGS. 1A-1K, a method for introducing a substance intoan intervertebral disc is illustrated schematically. As seen in FIG. 1A,an intervertebral disc D includes an annulus fibrosis AF surrounding anucleus pulposus NP, and is positioned adjacent a spinous process of avertebra V. Anatomically, the disc D is sandwiched between two vertebraeof the spine (not shown), which lie on top of and beneath the disc D.

In one embodiment, an introducer device 2 and a pointed obturator 4 areintroduced together through the skin S of a patient's back to positiontheir distal ends near the intervertebral disc D. Introducer device 2and obturator 4 may have any suitable dimensions, but in one embodimentintroducer device 2 is about 18-22 gauge and obturator 4 is about 20-25gauge.

As shown in FIG. 1B, obturator 4 is then removed, leaving introducerdevice 2 in place. As shown in FIG. 1C, an injection needle 6 is thenpassed through introducer device 2 and through the annulus fibrosis AFto position its distal tip in the nucleus pulposus NP. Position ofintroducer device 2 and/or injection needle 6 may be confirmed usingx-ray, fluoroscopy, or other suitable means. In some embodiments, wheninjection needle 6 is positioned in the nucleus pulposus NP, contrastdye may be injected through injection needle 6, and the appearance ofthe contrast dye in the disc as well as the patient's response to theinjection may be monitored. This part of the procedure generallydescribes a known discography procedure. In alternative embodiments,discography may be performed at a later time or no discography may beperformed.

After placing injection needle 6, a guidewire 8 may be passed throughinjection needle 6 into the disc, as shown in FIG. 1D. Injection needle6 may then be removed, as shown in FIG. 1E, and a catheter device 10 maybe passed over guidewire 8 through introducer device 2, as shown in FIG.1F. Catheter device 10 is described in further detail below, but in oneembodiment it may include two or more tubes, such as a guidewire tube 11and an injection or inflation tube 12, which may separate proximally toattach to multiple adapters or the like. Once catheter device 10 is inplace, introducer device 2 may be removed, as shown in FIG. 1G, andadapters 13 and 14 may be coupled with the proximal ends of tubes 11 and12. Adapters 13, 14 may facilitate guidewire passage, inflation of anexpandable member, injection of one or more substances into the discand/or the like.

Referring to FIG. 11, one or more anchoring members 16 disposed alongcatheter 10 are deployed to maintain a distal portion of catheter 10 inthe disc. In one embodiment, anchoring member 16 comprises an expandableballoon, but as is described in more detail below, many other types ofanchoring members may be used in various alternative embodiments. Asshown in FIG. 1J, once anchoring member 16 is deployed, guidewire 8 maybe removed. In some embodiments, as in FIG. 1K, a marker expandablemember 17 may be deployed outside the patient's body. With anchoringmember 16 and thus the distal portion of catheter 10 in place in thedisc, one or more substances are introduced into the disc throughcatheter 10.

It may sometimes be desired to leave the needle 6 which introduced thecatheter into the disc space in place to facilitate advancing andretracting the catheter. Use of a conventional needle having a sharpenedtip as illustrated in FIG. 1L, however, presents a risk of damaging thecatheter, particularly as the catheter may be retracted proximallythrough the needle. Thus, it may be preferred to employ an introducer“needle” having a blunt, rounded, or other atraumatic tip, asillustrated in FIG. 1M. In one embodiment, the atraumatic tip can besquare-cut and the edges rounded to form a smooth surface which will notdamage the catheter as it is advanced or retracted through the lumen ofthe needle. The tip could also be made of a softer material, a moreflexible material, be coated with a lubricious material or otherwisemodified to reduce the risk of damaging the catheter. When using aneedle having an atraumatic tip, the needle may be introduced using astylet having a sharpened tip.

When the catheter is delivered through a needle, either a sharpenedneedle as illustrated in FIG. 1L or atraumatic needle as illustrated inFIG. 1M, it will often be desirable to remove the needle. If thecatheter has a proximal hub or other enlarged features, it may not bepossible to draw the needle proximally over the enlarged structure. Insuch cases, it will often be desirable to use a needle 6 having an axialslot 6A, optionally covered by a frangible outer sheath, cover, or tube7. The width of the slot 6A will be sufficient to permit the catheter topass, and the outer tube or sheath 7 prevents accidental passage of thecatheter through the slot 6A while the catheter is being introduced.Thus, the material of the tube 7 should be strong enough to contain thecatheter during delivery, but still provide for easy longitudinaltearing when it is desired to withdraw the needle over the catheter.Suitable materials include polyester, PET, FEP, PTFE, polyolefins,nylons, PVCs, neoprenes, and other materials. Many of the materials maybe heat-shrunk over the needle shaft. The needle shaft will typically bea metal, such as stainless steel or nitinol, but could also be composedof a polymer having sufficient strength such as a polycarbonate, apolyethylene, PEEK, a nylon, a polypropylene, or the like. The axialslot 6A may be formed in the needle by cutting or machining the opening,typically for metal needle shafts, or by extruding the material that hasa C-shaped cross-section, typically for polymers. Although usually beingstraight, the longitudinal opening 6A could have other geometries, suchas spiral, zigzag, or other arbitrary shape. The outer tube 7 may beopened by tearing, shearing, and the like, and may be pre-scored,perforated, or otherwise weakened to assist in separation. In additionto heat -shrinking, the outer tube could be attached to the shaft of theneedle by melting, adhesives, or the like.

The method just described is but one embodiment of a technique forplacing and anchoring a distal portion of a catheter within a disc andintroducing a substance therein. In various alternative embodiments, anynumber of suitable changes to the technique, such as additions ordeletions of various steps, use of varied devices and the like, may bemade without departing from the scope of the present invention.

FIGS. 2A and 2B illustrate part of an alternative embodiment of a methodfor passing a catheter device 20 into a disc for introducing one or moresubstances. In this embodiment, rather than employing a guidewire passedthrough an injection needle, catheter device 20 is passed through anintroducer device 22 with a pointed stylet 24 extending through a lumenof catheter 20 and out its distal tip. Stylet 24 enables catheter 20 tobe passed through the tough annulus fibrosis AF without the help of aguidewire and injection needle. Stylet 24 is then removed, as shown inFIG. 2B, to leave catheter 20 in position for anchor deployment andsubstance introduction.

Stylets such as illustrated in FIGS. 2A and 2B are usually much morerigid in both the axial and bending directions than the catheter whichis being advanced. The catheter can freely slide relative to the stylet.There is a risk that the catheter will differentially deflect andseparate from the stylet. In order to prevent such separation, the tipsof the stylet and the catheter can be modified to hold them together.For example, the stylet 24 may have a step or other geometry at itsdistal end which mates with a complementary shape formed inside thedistal tip of the catheter 20, as illustrated in FIG. 2D. Alternatively,the stylet 24 may have a tapered or cone-shaped distal end which mateswith a similar shape in the distal end of the catheter 20, asillustrated in FIG. 2E. The distal ends of the catheter and the styletcould also be modified to have mating threaded ends for a more securebut still releasable attachment.

Optionally, the distal tips of the stylets may be made to be radioopaquein order to enhance fluoroscopic imaging. For example, at least thedistal portions of the stylets 24 could be composed at least partly, orplated with, a radioopaque material such as platinum, iridium, or gold.The remaining portions of the stylet may be made from stainless steel,nitinol, or other materials having the desired column strength andflexibility to provide for “pushability” of the combination of stylet 24and catheter 20. By providing a stylet tip which is inherentlyradioopaque, the number of components and the profile or cross-sectionof the combined device (including both the stylet 24 and catheter 20)may be reduced. Reducing profile is advantageous, since it facilitatesentry into the disc space through the annulus fibrosis.

Referring now to FIG. 2C, a method for introducing a catheter device 21into a disc to inject one or more substances may be facilitated in oneembodiment through use of a split-away introducer device 23. Split-awayintroducer device 23 may be used just as the introducer devices havebeen described above. Rather than removing split-away introducer device23 by sliding it off the proximal end of catheter device 21, however,split-away introducer device 23 is split along its length to be removedfrom catheter device 21. Split-away introducer device 23 may beconstructed from any suitable material or materials so as to readilytear, crack, fissure, rip or separate along the length of needle 23.Splitting may be accomplished by including a perforation, thin sectionor other weakness along the length of needle 23.

Typically, once a catheter device is in place, with a distal portionresiding in a disc and one or more anchoring members deployed tomaintain the catheter's position, the patient is instructed to assume aposition or perform a task that typically causes the patient pain, suchas bending over to pick up an object or the like. A substance is thenintroduced into the disc, and the patient is asked to relate whetherpain is lessened, eliminated, remains the same or the like. In variousembodiments, the patient is asked to rate the experienced pain on ascale of 1 to 10 before and after introduction of substances into thedisc. In one embodiment, the substance introduced is an anesthetic oranalgesic, and thus may alleviate the patient's pain if injected intothe disc that is actually causing the pain. In some instances multipleinjections are performed, and one or more injected substances may beplacebos, to test the accuracy of the test results. Again, such testingmay be performed either alone or before or after traditionaldiscography. In some embodiments, multiple discs of one patient may beaccessed and tested. Also in some embodiments, testing may be performedover a prolonged period of time, to test multiple discs and/or toenhance the accuracy or certainty of test results.

In various embodiments, any of a number of different substances may beintroduced into a disc. For different purposes, such as diagnosis ortreatment of discogenic pain, study purposes or experimentation or thelike, introduction of different substances may be warranted. Examples ofpossible substances that may be introduced into a disc include, but arenot limited to anesthetics; analgesics; antibiotics; hydrating agentssuch as hypotonic saline, isotonic saline or hypertonic saline;supportive agents such as a hydrogel, ethylene -vinyl alcohol copolymer,Dimethyl Sulfoxide or Tantalum; prolotherapy agents such as sodiummorrhuate, cod oil, phenol, minerals or ethyl alcohol; and/or otheragents such as collagen, stem cells, Osteogenic Protein-1, ethanol,alcohol, steroids, radio-opaque contrast agents, ultrasound contrastagent, Bone Morphogenetic Protein (BMP), BMP-2, BMP-4, BMP-6, BMP-7,BMP-12, Serotonin 5-HT2A receptor inhibitors, LMP-1, TIMP-1, TGF-1,TGF-2, Rofecoxib, Ketorolac, Glucosamine, Chondroitin Sulfate, Dextrose,DMSO, non -steroidal antiinflammatory drugs, ibuprofen, naprosyn,Bextra, Vioxx, Celebrex, indomethacin, botulinum toxin, capsaicin,vanilloid agonists, vanilloid antagonists, VR1, VRL-1, steroids,methylprednisolone or chymopapain. Substances may be delivered in abiodegradable or time release vehicle to provide long-termadministration of the substances.

Examples of anesthetics and analgesics include, but are not limited tolidocaine, chloroprocaine, mepivacaine, ropivacaine, xylocaine,prilocaine, morphine, bupivocaine, marcaine, 2-chloroprocain, fentanyl,diamorphine, meperidine, methadone, alfentanil, hydromorphone,lofentanil, sufentanil, buprenorphine, other opoids, adrenergicagonists, somatostatin analogs, calcium channel blockers,N-methyl-D-aspartate receptor antagonists, ketamine, benzodiazepines,klonidine, tizanidine, midazolam, levorphanol, heterocyclicantidepressants, nonheterocyclic, serotonin-enhancing antidepressants,GABA analogues, psychogenic amines, somatostatin, octreotide, SNX-111,midazolam, methylprednisolone acetate, Aristospan, ethyl chloride,etidocaine, linocaine, triamcinolone diacatate, Astramorph, Duramorph,Dilaudid, Sensorcaine MPF, Baclofen (Lioresal), Clonidine, baclofen,codeine, neurontin and Demerol. Examples of antibiotics include, but arenot limited to, Penicillins, Cephalosporins, Tetracycline, Erythromycin,Clindamycin, Vancomycin, Bacitracin, Doxycycline, Ampicillin, Levaquin,Metronidazole, Azithromycin, Ciprofloxacin, Augmentin, Bactrim, TMP-SMX,Rocephin, Gentamycin, Keflex and Macrobid.

As already mentioned, in some embodiments the method further includesleaving the catheter device in place to provide treatment of a patient'sback pain, such as with anesthetic or analgesic agent(s) or othersubstances. In some embodiments, the catheter device may be coupled withan implantable pump, injection port or other device to provide suchtreatment.

Referring now to FIGS. 3A and 3B, a distal portion of a catheter device30 according to one embodiment is shown in perspective view andcross-sectional view, respectively. Catheter device 30 suitably includesa catheter body 32, which includes an expandable anchoring member 36,houses an inflation tube 34 and an injection tube 38, and has severalradioopaque markers 33 disposed along its distal portion. Anchoringmember 36 enables a distal portion of catheter device 30 to bemaintained in a position within a disc. Inflation tube 34 is used toexpand anchoring member 36, which in the embodiment shown comprises anexpandable balloon. Injection tube 38 is used to introduce one or morefluids into the nucleus pulposus of the disc. Radioopaque markers 33facilitate visualization of the distal portion of catheter device 30 sothat its location may be assessed before, during or after a diagnosticor therapeutic procedure.

In various embodiments, the distal portion of catheter device 30 mayhave one or more features that facilitate advancement of the distalportion through an annulus fibrosis of an intervertebral disc. A distalportion having one or more such features is generally referred to as“self-introducing.” Therefore, by “self-introducing” it is meant simplythat the distal portion has one or more features for facilitating itspassage through annulus fibrosis tissue. Such features may include, forexample, one or more sections on a catheter shaft that are stiffer thanadjacent sections to help make the shaft pushable. Another feature maycomprise a tapered or pointed distal tip for piercing through annulusfibrosis. In some embodiments, catheter device 30 may be coupled with aremovable, pointed stylet. These or any other suitable features may beincluded in a distal portion of catheter device 30 for facilitatingpassage through an annulus fibrosis.

The various components of catheter device 30 may be constructed from anysuitable materials and may have any suitable shapes, sizes, dimensionsor the like in various embodiments. In one embodiment, for example, thecross-sectional diameter of catheter body 32 decreases along its lengthfrom its proximal end to its distal end. Such a tapered configurationmay allow catheter device 30 to be easily introduced through anintroducer device. The outer diameter of catheter body 32 will alsogenerally be slightly smaller than an inner diameter of an introducerdevice. In one embodiment, for example, catheter body 32 has an outerdiameter of about 2 mm or less along at least part of its length.

In various embodiments, catheter body 32 may comprise a rigid singlepolymer or a composite consisting of reinforced metallic or polymericcomponents. Metallic components may include, for example, stainlesssteel, nitinol or other superelastic alloys. Polymers may include, butare not limited to Polyetheretherketone (PEEK), Polyether Block Amide(PEBAX), Nylon, Polyester, Polyolefin, polyamide, Polyimide,Polycarbonate, Polypropylene, Fluorinated Ethylene Polymer (FEP),Perfluoroalkoxy (PFA), Polytetrafluoroethylene-Perfluoromethylvinylether(MFA), Polyurethane or Low density polyethylene (LDPE). Such materialsmay be reinforced with coils or braids in some embodiments. Thematerials may also be coated internally or externally with materials theresist friction such as Teflon (Poly-Tetra-Flouro-Ethylene), hydrophilicmaterials, parylene or the like.

In various embodiments, catheter shaft may include one or moreradiopaque markers 33 and/or may be made from one or more radiopaquematerials to facilitate visualization. Such radiopaque markers/materialsmay include, but are not limited to, gold, Platinum, Iridium, Tungsten,Tantalum, resins containing Barium Sulfate, Bismuth trioxide or Tungstenand/or the like.

Anchoring member 36 may also be made of any suitable materials now knownor discovered in the future, according to various embodiments. Forexample, expandable anchoring member 36 may comprise flexible polyvinylchloride (PVC), Polyethylene, Polyether Block Amide (PEBAX),Polyethylene Terepthalate (PET), Polyester, Nylon, Polyurethanes,Polyether Block Amide (PEBAX), Polyolefins or any suitable combinationthereof. Various adhesives may be used to attach anchoring member 36 tocatheter shaft 32 or for any other suitable purpose. Any suitableadhesive(s) may be used, such as but not limited to, light activatedacrylics, light activated cyanoacrylates, light activated silicones,heat activated adhesives, ambient curing adhesives, cyanoacrylates,epoxy adhesives, and/or polyurethane adhesives. Various parts ofcatheter device 30 may also be attached using alternative means, such asfriction fitting, snap fitting, screw fitting, application of energysuch as thermal or radiofrequency energy, and/or the like.

Referring now to FIGS. 4A and 4B, in another embodiment a catheterdevice 40 comprises an outer shaft 42, an inner shaft 44, and ananchoring member 46 coupled with both outer shaft 42 and inner shaft 44.Shafts 42, 44 are axially slidable relative to one another, such thatwhen inner shaft 44 is moved proximally relative to outer shaft 42,anchoring member 46 buckles outward to perform its anchoring function,as shown in FIG. 4B. In this embodiment, inner shaft 44 acts as aninjection lumen and also possibly as a guidewire lumen, and no inflationlumen is needed. In one embodiment, anchoring member 46 may beconstructed as a cylinder with slots or other shapes cut out of it toform column-like buckling structures. Components of this embodiment maybe made of the same or different materials as just described.

An alternative embodiment of a catheter device 50 is shown in FIGS. 5Aand 5B. Here, catheter device 50 includes an outer shaft 52, an innershaft 54, an anchoring member 56 coupled to outer shaft 52 and innershaft 54, and a sheath 58 slidably disposed over outer shaft 52. Whensheath 58 is disposed over anchoring member 56, as in FIG. 5A, anchoringmember 56 remains in an undeployed state suitable for delivery into thedisc. When sheath 58 is retracted and/or outer shaft 52 is advanced, asin FIG. 5B, anchoring member 56 may be deployed. In some embodiments,anchoring member 56 may be deployed via buckling or via inflation, asdescribed above. In other embodiments, anchoring member 56 mayself-expand, for example if it is comprised of shape-memory orspring-loaded materials that expand when released from sheath 58.

Referring now to FIGS. 6A and 6B, in another embodiment a catheterdevice 60 includes an outer shaft 62 having an expandable anchoringportion 66 and an inner shaft 64. Expandable anchoring portion 66generally comprises a buckling portion of outer shaft 62 and may includemultiple features such as small cut-outs 68 and larger openings 67. Whena proximal portion of outer shaft 62 a is moved toward a distal portionof outer shaft 62 b, anchoring member 66 buckles, due to features 67,68, thus providing the anchoring function.

With reference now to FIGS. 7A and 7B, another embodiment of a catheterdevice 70 is illustrated having a catheter shaft 72 and retractable tineanchors 76. Tine anchors 76 may be deployed from a retracted state, asin FIG. 7A, to a deployed state, as in FIG. 7B. Tine anchors 76 may bepre-bent so that they readily take on a pre-determined shape whendeployed out of catheter body 72, and anchors 76 may be made of metal,such as stainless steel or shape-memory metal such as Nitinol, polymers,or any other suitable material. In various embodiments, tine anchors 76may be deployed either by pushing them out of their housing lumens or byreleasing them from constraint to allow them to self-deploy.

In other embodiments, and with reference now to FIGS. 8 and 9, a distalportion of a catheter device may deform to anchor the distal portion inthe disc D. In one embodiment, as in FIG. 8, a catheter device 80 mayhave a distal portion 82 that deforms to a spiral configuration. Inanother embodiment, as in FIG. 9, a catheter device may have a distalportion 86 that deforms to a zig-zag configuration. Any other suitableshape for a distal portion may be used in various embodiments.Deformation of a distal portion may be achieved by any suitable means,such as by using a shape-memory or spring-loaded material, by using apull cord, tendon, stylet or other actuator to deform the distal portionor the like.

FIGS. 10A-10D illustrate that an anchoring member of a catheter devicemay have any suitable shape, size, configuration, orientation to thecatheter shaft or the like, in various embodiments. In the embodimentshown in FIG. 10A, for example, an anchoring member 100 of a catheterdevice is shown in cross-section within a disc D between two vertebraeV. In this embodiment, anchoring member 100 has a circularcross-sectional shape and is disposed concentrically over a cathetershaft 102 of the catheter device. In the embodiment shown in FIG. 10B,an anchoring member 104 is asymmetrically attached to a catheter shaft106 and has a non-circular, asymmetric shape. In the embodiment shown inFIG. 10C, an anchoring member 108 is concentrically disposed over acatheter shaft 110 and has an elliptical cross-sectional shape. FIG. 10Dshows a longitudinal view of a catheter device 112 having anapproximately conical-shaped anchoring member 114. This embodimentdemonstrates that anchoring member 114 may have not only variouscross-sectional shapes but also various longitudinal shapes in variousembodiments.

Referring now to FIG. 11, yet another embodiment of a catheter device116 advanced over a guidewire 120 includes an anchoring member 118 thatattaches to annulus fibrosis AF of a disc to maintain the distal portionof device 116 in the disc D. Here, anchoring member 118 comprises aspiral needle that may be screwed, twisted or otherwise driven into theannulus fibrosis AF.

FIG. 12 shows another embodiment of a catheter device 122, in this casecomprising a catheter shaft having threads 126 for anchoring in anannulus fibrosis. In various embodiments, any other suitable means foranchoring into the annulus fibrosis may be used, such as hooks, anchors,barbs, T-tags or the like.

With reference now to FIG. 13, in another embodiment a catheter device128 includes two an outer anchoring member 130 for anchoring outside theannulus fibrosis AF and an inner anchoring member 132 for anchoringinside the disc D, typically in the nucleus pulposus NP. As shown here,anchoring members 130, 132 may comprise expandable members, such asinflatable balloons. In other embodiments, alternative anchoring membersmay be used, more than two anchoring members may be used and/or thelike. Using two anchoring members 130, 132 may further ensure that adistal portion of catheter device 128 remains in position within thedisc.

As discussed above, and referring now to FIG. 14, in some embodiments acatheter device 134 having an anchoring member 136 may be used fortreating discogenic pain. In some embodiments, catheter device 134 maybe coupled with an implantable device 138 for providing treatment,implantable device 138 being positioned under a patient's skin S or inany other suitable location in the patient's body. Implantable device138 may comprise, for example, an implantable pump with or without adrug reservoir, an implantable drug infusion/injection port,transcutaneous electrical nerve stimulation (TENS) device or any othersuitable device in various embodiments. Substances introduced into thedisc DS via catheter device 134 and implantable device 138 may includeany of the substances listed above, such as an anesthetic or analgesicto relieve pain. Implantable device 138 may be left in the patient forany suitable length of time to provide treatment.

In one embodiment, implantable device 138 may comprise an implantablepump 139. In some embodiments the pump may be programmed to deliver drugfrom an attached reservoir into the nucleus pulposus at a constant rate,at programmed intervals, upon triggering by the patient or physicianthrough the use of an external device capable of communicating with thepump, such as but not limited to magnetic reed switches, electromagneticwave communication devices such as visible light, radio-wave, microwave,or short-wave, or wireless communication protocols such as Bluetooth. Insome embodiments, the patient may control pump-mediated drug delivery byphysically manipulating switches, toggles, or other similar devicescoupled with the pump. Optionally, the implantable pump may beconfigured to store data related to the usage pattern of the drug by thepatient. This information could be downloaded for review throughwireless communication with an external device such as those listedabove. In embodiments having a drug reservoir, the implantable devicemay also include an injection port to allow the reservoir to be refilledtranscutaneously.

The distance between the disc D and the surface of the skin can changeas the patient moves. To prevent the distal end of catheter device 134and anchoring member 136 from pulling out of the nucleus, a mechanismfor providing strain relief in the attachment between catheter device134 and implantable device 138 may be provided. In one embodiment, forexample, catheter device 134 may extend between implantable device 138and the disc D in a circular, spiral, curved, serpentine, or otherwisenonlinear path, thus providing an amount of slack (as shown in brokenline) in catheter device to allow for movement between the disc D andthe implantable device 138 with patient movement.

Implantable catheter devices, such as catheter device 134, will beprovided with anchoring members 136, which typically may be inflatableballoons or other structures. Preferably, the catheter devices 134 willhave an integral balloon inflation lumen, or will be provided withseparate balloon inflation tubes to permit inflation of the balloonanchor 136 after proper positioning of the catheter. Rather than using astopcock or other valve structure for providing balloon inflation, thecatheter devices 134 may be provided with self-sealing septum structuresat an end of the inflation lumen. Optionally, the catheter devices 134could also include substance delivery lumens which also terminate at aproximal end in a self-sealing septum to allow for drug and substancedelivery after the device has been implanted. Suitable septum materialsinclude silicone, rubber, latex rubber, isoprene rubber, polyisoprenerubber, and numerous other known materials.

Alternatively, a balloon inflation lumen on the catheter device 134 orseparate balloon inflation tube could be sealed using a suture, clip,filament loop, or any of a variety of other external closure elements.Such clips or crimps could be formed from a spring-like material, suchthat they can be pre-shaped to collapse the inflating lumen.Alternatively, the clips or crimps could be deformable so that theycould be tightened over the balloon inflation lumen to effect closure.In both cases, multiple closure members could be placed at differentpoints along the balloon inflation lumen in order to enhance the seal.Moreover, the closure elements could be removable to permit deflationand reinflation of the balloon, should it be desired during or afterimplantation. The closure elements could also be removed to permitdeflation of the balloon for explantation of the catheter.

As a further alternative, the balloon inflation lumen could be sealedusing heat, adhesives, or ultrasonic energy, resulting in melting orfusing of the lumen. Heat can come from a variety of sources, includingelectrical resistance heaters, electrical inductive heaters, or thelike.

To facilitate delivery of a distal portion of a catheter device into adisc D, and with reference now to FIG. 15A, some systems include ashaped guidewire 146 configured to maintain a distal portion ofguidewire 146 within the disc during delivery of the catheter device. Asshown in FIG. 15A, guidewire 146 is delivered through an injectionneedle 142, which has been delivered through an introducer device 140.When a distal portion of guidewire 146 a is advanced out of the distalend of injection needle 142, it assumes a shape, in this case a spiralshape, which secures distal portion 146 a in the disc. Guidewire 146 maybe formed of any suitable material to provide for such a shape change,such as but not limited to shape-memory materials such as Nitinol,spring stainless steel or the like. In some embodiments, a distal tip ofthe guidewire includes one or more radiopaque markers, coils or thelike, or is made of one or more radiopaque materials.

As shown in FIG. 15B, in another embodiment a guidewire 148 has a distalportion 148 a that assumes a zig-zag shape upon being advanced beyondthe distal end of injection needle. In various embodiments, guidewiresmay have distal portions with any suitable shapes for anchoring in thedisc D.

Referring now to FIGS. 16A and 16B, in one embodiment a guidewire 150has a double-wire configuration for enhancing its ability to maintainits position within a disc D. Double-wire guidewire 150 includes twowires joined at their distal ends, the attachment being achieved bywelding, soldering, bonding, gluing, folding a single wire, or any othersuitable technique. As shown in FIG. 16A, a distal end of guidewire 150a may be delivered into the disc D in a relatively straight, undeployedconfiguration. Double-wire guidewire 150 is then deployed, as shown inFIG. 16B, by differentially pushing or pulling on one of the wires ofthe double wire guidewire causing distal portion 150 a to deform. In itsdeployed state, double-wire guidewire 150 is less likely to dislodge orpull out of the disc D than a single-wire guidewire.

As described thus far, the disc space has been accessed using atransannular approach. As illustrated in FIGS. 14A and 14B, however, insome cases it may be preferable to approach the nucleus pulposus NPthrough the adjacent vertebral body V in a transosseous approach, i.e.,across the bone. Use of a transosseous approach avoids the necessity ofperforming an annulotomy, thus avoiding puncturing and potentiallydamaging the annulus fibrosis AF. In the transosseous approach, thecatheter 134 passes through the vertebral body V and into the discspace. As shown in FIG. 14A, the catheter 134 may pass through a singlevertebral body into the adjacent disc space. In some cases, however, itmay be desirable to pass the catheter 134 through multiple disc spaces,as shown in FIG. 14B, deploying the anchoring member 136 in thedistal-most disc space, or alternatively in one of the vertebral bodies.Such an approach is advantageous since it permits treatment of multipledisc spaces simultaneously. The disc space or spaces could be accessedfrom the superior or inferior vertebral body. The transosseous approachcould be performed by drilling or chiseling an access path through thevertebral body using a twist drill bit, a abrasive burr, sharp chisel,or other tools known in the art of surgery. The tool utilized to makethe access path in the bone can be introduced alone or through theintroducer needle. In some cases it may be necessary to pre-bend theintroducer needle or tool to achieve the correct angle for the accesshole in the vertebral body.

With reference to FIGS. 17A and 17B, one embodiment includes one or moreadapters 160 for removably coupling with one or more proximal ends of acatheter device 162. Adapter 160 is typically coupled with catheterdevice 162 after the distal end of catheter device 162 is in placewithin the disc and after the introducer device, stylet or the like hasbeen removed, although in alternative embodiments adapter 160 may becoupled with catheter device 162 at any other suitable time. Adapter 160may comprise or resemble a Touhy Bourst adapter, compression fitting,instant tube fitting, or other similar adapter or connector. In oneembodiment, adapter includes a distal sealed connector 164, a proximalsealed connector 166 having an injection port 167, an anchoring memberinflation port 168, and a stopcock 169 for controlling fluid flowthrough inflation port 168. Injection port 167 is in fluid communicationwith a lumen of catheter device 162 and may be used for injection ofsubstance(s) into the disc and/or for passage of a guidewire. Injectionport 167 and inflation port 168 may include leur fittings, press fits,barbs or any other suitable tube connection methods. Proximal sealedconnector 166 and distal sealed connector 164 may be activated byrotating the sealed connectors on threads, automatic press activation,spring actuation or any other suitable method.

In addition to implantable devices and proximal adapters, a catheterdevice in some embodiments may be coupled with one or more automatedinjection devices. Such injection devices may facilitate testing of onedisc or multiple discs over an extended period of time, with onlyperiodic supervision by a physician, nurse or other clinician. Forexample, the patient could remain in clinic or hospital room while aseries of substances are introduced into a disc, while the patientassumes different positions to test the pain response, while substancesare injected into multiple discs through multiple catheter devicesand/or the like. Such an automated system may facilitate and enhancediagnosis of discogenic pain by allowing for more extensive testing. Insome embodiments, such a system may also include a device for recordingpatient pain responses, such as an instrument that allows a patient torecord pain felt before and after an injection on a scale from 1 to 10and/or to relate the pain felt to the patient's usual back pain.

Although the foregoing is a complete and accurate description of theinvention, a number of changes, additions, variations and the like maybe made to various embodiments without departing from the scope of theinvention. Therefore, the description is provided primarily forexemplary purposes and should not be interpreted to limit the scope ofthe invention as set forth in the claims.

1. A method comprising: inserting a distal portion of an elongated bodyinto a nucleus pulposus of an intervertebral disc in a patient's body;deploying an anchor, by expanding the anchor within the nucleuspulposus, to secure a distal portion of the elongated body in theintervertebral disc; administering an anesthetic into the intervertebraldisc in the patient while the distal portion of the elongated body issecured in the intervertebral disc; and identifying the intervertebraldisc as a source of pain wherein identifying comprises recording whetherthe anesthetic has alleviated the discogenic pain.
 2. A methodcomprising: identifying a location of pain within a patient's spine;inserting a distal portion of a fluid conduit into an intervertebraldisc at the location in the patient's spine; anchoring the fluid conduitin the intervertebral disc by expanding a first expandable member withina nucleus pulposus of the intervertebral disc; administering ananesthetic into the intervertebral disc in the patient while the fluidconduit is anchored in the intervertebral disc; and determining whetherthe intervertebral disc is a source of the pain within the patient'sspine, wherein anchoring the fluid conduit comprises expanding a secondexpandable member adjacent the intervertebral disc.
 3. A methodcomprising: identifying a location of pain within a patient's spine;inserting a distal portion of a fluid conduit into an intervertebraldisc at the location in the patient's spine; anchoring the fluid conduitin the intervertebral disc by expanding a first expandable member withina nucleus pulposus of the intervertebral disc; administering ananesthetic into the intervertebral disc in the patient while the fluidconduit is anchored in the intervertebral disc; determining whether theintervertebral disc is a source of the pain within the patient's spine;and injecting the anesthetic through the fluid conduit into theintervertebral disc, wherein determining comprises determining whetherthe injected anesthetic alleviates the pain.
 4. A method comprising:placing a distal portion of a catheter into an intervertebral disc in apatient's body, wherein the catheter includes at least an injectionlumen and an inflation lumen; expanding an anchoring member within theintervertebral disc, the anchor member disposed on the distal portion ofthe catheter; administering an anesthetic into the intervertebral discin the patient while the anchor member is expanded in the intervertebraldisc; and determining a source of pain within the patient's spine,wherein determining the source of pain comprises administering theanesthetic through the catheter into the intervertebral disc to see ifthe pain is alleviated.
 5. A method comprising: placing a distal portionof a catheter into an intervertebral disc in a patient's body, whereinthe catheter comprises an anchoring member; expanding the anchoringmember within the intervertebral disc to anchor the catheter within theintervertebral disc; administering an anesthetic into the intervertebraldisc in the patient before the catheter is removed from theintervertebral disc; and determining a source of pain within thepatient's spine, wherein determining the source of pain comprisesinjecting a substance into the intervertebral disc through the catheterto determine the source of pain within the patient's spine.
 6. A methodcomprising: placing a distal portion of a catheter into anintervertebral disc in a patient's body, wherein the catheter comprisesan anchoring member; expanding the anchoring member within theintervertebral disc to anchor the catheter within the intervertebraldisc; and administering an anesthetic into the intervertebral disc inthe patient before the catheter is removed from the intervertebral disc;determining a source of pain within the patient's spine; and deploying asecond anchoring member adjacent the intervertebral disc and expandingthe second anchoring member within the patient's body adjacent theintervertebral disc to anchor the catheter within the intervertebraldisc.
 7. The method according to claim 6, wherein the anchoring memberis configured to increase a cross-sectional diameter of the catheter atone or more locations on the catheter.
 8. The method according to claim6, wherein the anchoring member comprises an expandable member.
 9. Themethod according to 6, wherein the anchoring member comprises a balloon,and deploying the anchoring member comprises inflating the balloon. 10.A method comprising: placing a distal portion of a catheter into anintervertebral disc of a patient, wherein the catheter comprises ananchoring member; expanding the anchoring member within theintervertebral disc to anchor the catheter within the intervertebraldisc; administering an anesthetic through the catheter into theintervertebral disc in the patient, wherein the patient suspects thatsuch disc may be a source of pain; determining whether the anesthetichas relieved the pain; and if the anesthetic has relieved the pain,performing further interventional treatment on the intervertebral disc,wherein administering comprises anchoring the catheter in the disc priorto delivering the anesthetic through the catheter.
 11. A method as inclaim 10, wherein the patient repositions his or her spine in a mannerwhich would be expected to cause pain in the intervertebral disc.